Question

While watching a star, you see it moves 15 degrees across the sky. How long have you been watching it?

a. 3 hours
b. 15 minutes
c. 1 hour
d. 1 minute
e. 15 seconds

Answer 1

A star moving 15 degrees across the sky indicates it was watched for 1 hour, based on the Earth's rotation rate of 15 degrees per hour.

Step-by-step explanation:

The movement of stars across the sky is due to the Earth's rotation. When observing such a movement, it is essential to consider that the Earth rotates 360 degrees in 24 hours, which is equal to 15 degrees per hour. Therefore, if a star moves 15 degrees across the sky, you have been watching it for 1 hour.